vellicate

(verb) touch (a body part) lightly so as to excite the surface nerves and cause uneasiness, laughter, or spasmodic movements. Synonyms: tickle, titillate.

(verb) irritate as if by a nip, pinch, or tear. Synonyms: pinch. Examples: "Smooth surfaces can vellicate the teeth." "The pain is as if sharp points pinch your back."